Twist-drill.



ER. 'rwxs'r DRILL;

APPLICATION ED 1'33, 18, 1910. I Patented'Apr. 11,1911.

1 E. B. MATH IIL mam Bataan Arum or aoonnsrrnn, NEW YORK, AssmNon'ro MA TIN MIN'GTD. or Bno'cKPow-r, rmw roan.

' 'r'w 's'r-DmLL.

v Specification 01 Letters ratent. 7 Application filed February 15, 1910.. .ra1'm. 44,536; v

Pa -shad A li-.111, 1 911.

Be it known that LELIs A citizen of the United States, and a resident of Rochester, in the county of-Monroe and State dfjN'ew York, haveinvented a new and j Improved Twist-Drill, of which the following is a full,- clear,'and exact description.

- Among the principalpresent inventl'on hasin view are: To provide a drill of the character specified where in the cutting area is reduced; to provide a I drill of the character specified wherein is.

" formed a central-guidefor the operation" of the tool;- ,to provide a construction .for a 'uiding' core '.formed in the metal by the.v p

d 56 is extended upward intolthe body central and narrowed section of the connecting web thereof. and

drill ofthe character specified having a.

throatedcentral opening for the passage of a filling-operation; and to rovide a drill of the character specified o vsimple," efficient and economical construction.

"One embodiment of the present invention- I is disclosed in the structure illustrated in the accompanying drawingiain which like char actors of reference e parts inall the views, and in which- Figure I is a side view of atwist drillcon -i structed in" accordance with. the, present invention; Fig.2isa similar view,showing the drill in 'operatlon, the metal plate: in conjunction ,w-herewith it is shown being illusinaccordance. with this invention, a fragment of the cutting point'being broken away to show in section thefor- -3 inclusive, viewed'from the cuttin used; above, thefur .tion i'stwo-fol mation, of the connecting web; and Fig. 4 is an end, View of the tool shown in Figs.1 1 to.

Stated in" language difi'erent roin that ose of the present inven- 's'ection'of the center of the drill, there is drill-,by reasonv of the fact that'the point is avoided thedead ornon-rotated oint, which in. its; operation retards the s1 (ing of the forced through-the metal only when the surrounding walls" are, by the. rotating ends, broken down. The core which the uncut cenq trallj locatedmetal thus forms, operates as a most-'efiicient and desirable guide for cen- 'tralizing'the B. MATHER, a

objects which the note corresponding line with the slot '6,is,

y: eliininating'a certain unequal temper or composition.

As. a resu to servethe first mentioned -purpose, the cuttin edge of the tool is materially reduced,

an further, the elimination or'reduction of the cutting edge, is'directed' to. that part of the ed eofi'errng the greatest resistance {of the sin ageof the tool-in, the operation of drilling.

To orm 'a tool in accordance with the its operation, thereby avoiding the drifting tendency in metal of t of the construction designed present 'inventi.on','the usual twist drill 5 is provided attheapex of thecone end-with a slot 6. The slot6 is formed to the width which 1 practice dictates is the most desired for various qualities and kinds of metal. The slot drill and follows the terminates atthe upper end 'in an inclined surface 7. The surace 7 is formed to. a

single incline, its purpose being to ex& tend to one side of the metal core raised from the bottom of the hole being bored, to defiect thesame into a channel 8' on one side oi the 'web connectingthe cutting edges of the tool. For. the purpose of, description I-will callt-he inclined surface a throat. A core 9, formed by the omission to cut the metal in by the throat 7, forced.

into the channel 8. In certain metals the core 9 will remain intact,-being delivered by the inclined throat 7 into the channel of-the drill into which the throat 7 leads. The core I will lie in said channel assuming the spiral arrangement of these-me.

In certain qualities vof metal the core will break away 'at near qualities of metal the core, from itsbase tov the throat 7, will remain intact. 'If the core breaks, as above stated, the broken particle is led out'throug'h the channels 8 and 10in the usual manner for drills of-this character.

It will be noticed by referenceto the illustration. shown in Fig. 1, that 'the cutting edge of the tool is materially'reduced by the elimination of the a ex of the cutting edge.

The immediate resu tDf' this elimination is of the the throat 7. In all that the metal Cl lt loy the said tool is diminished and the sinking speedof the spool is proportionallyv increased.

I-Izrving thus described my invention, What.-

I chum as Dd desire to secure byfLeb te rs Patent is v A twist drill having a vertically disposed; centrally located slot formed betweenrthe radial cutting edges 'of'said drill, said slot hm'ing an upper end Wall eXte ided across the said slot to form a downwardly inclined surface to deflectlaterally the core cut from v the metal.

In testimony whereof Iliave-s'igried this specification in the presence of rtwo sub's'eiib- 1 5 ".ing witnesses; I ELISHA BARKER MATHER.

Witnesses r CAROLYN W. :TOWNER, RAGE E. I TOWNERJ,

Copies of this patent may lee obtained for five cents each, by addressing the Commissioner of Patents; h

' Washington, DIG. j

in Letters Patent No.; 989,379.

[SEAL] Correction P New York, forlan improvement in Twist-Drills,

Signed and sealed this 25th day of July, A. 1 911, i

' It is herehy eertifiedthat the name of the assiglieein Letters Paterit No. 9'-39.) "79,

; grantedpApril 11, 1911, u 'p 01ithe application of Elisha: Barker Mather, of lrtoehester was erroneously ritten ahd t -14 m whereas said name should have been written a nd priiited I jtlorto'n rlfi'not, as shown by the reeords'ot assignlnent'in this office; andtl zt-the' .proper corrections have been made 'in the files and records of the Patent Ofii c eand I are-hereby niade insaid Letters Patent.

E; B; M OliEjj I Commissioner of Pdz fieatte that the metal (Hit by the said tool is diminished and the sinking speedof the spool is proportionallyv increased.

I-Izrving thus described my invention, What.-

I chum as Dd desire to secure byfLeb te rs Patent is v A twist drill having a vertically disposed; centrally located slot formed betweenrthe radial cutting edges 'of'said drill, said slot hm'ing an upper end Wall eXte ided across the said slot to form a downwardly inclined surface to deflectlaterally the core cut from v the metal.

In testimony whereof Ihave-s'igried this specification in the presence of rtwo sub's'eiib- 1 5 ".ing witnesses; I ELISHA BARKER MATHER.

Witnesses r CAROLYN W. :TOWNER, RAGE E. I TOWNERJ,

Copies of this patent may he obtained for five cents each, by addressing the Commissioner of Patents; h

' Washington, DIG. j

in Letters Patent No.; 989,379.

[SEAL] Correction P New York, forlan improvement in Twist-Drills,

Signed and sealed this 25th day of July, A. 1 911, i

' It is herehy eertifiedthat the name of the assiglieein Letters Paterit No. 9'-39.) "79,

; grantedpApril 11, 1911, u 'p 01ithe application of Elisha: Barker Mather, of lrtoehester was erroneously ritten ahd printed "i\'lert-i1i'Mi'not Whereas saidname should have been written a nd priii'ted I jtlorto'n rlfi'not, as shown by the reeords'ot assignlnent'in this office; andthzt-the' .proper corrections have been made 'in the files and records of the Patent Ofii c eand are he'rebymade insaid Letters Patent.

E; B; M OliEjj I Commissioner of Pdz fieatte Correction in film-ton illa'not, as shown Letters Patent Nor 989,379.

It is hereby certified that the name of the assignee in Letters Patent No. 989.379, granted .April 11, 1911, upon the application of Elisha Barker Mather, of ,ltochester, l

l New York,

for an improvement in Twist-Drills, was erroneously written and printed. Martin Minot whereas said name should have been written and printed by the records of assignment in this ofiice; and that the l proper corrections have been made in the files and records of the Patent Offiee and l are hereby made in said Letters Patent.

4 Signed and sealed this 25th day of July, A. D. 1911.

[SEAL] E. B. MOORE,

Commissioner of Patents. 

